Cylinder liner for opposed piston engines



Feb. 15, 1949. STEINER 2,461,853

CYLINDER LINER FOR OPPOSED PISTON ENGINES Filed Aug. 9, 1945 INVENTOR HHNS STE/NEE ATTORNEYS Patented Feb. 15, 1949 CYLINDER LINER FOR OPPOSED ms'ron ENGINES Hans- Steiner, Winterthur, Switzerland, assignor to Sulzer Freres, Soc Switzerland iete Anonyme, Winterthur,

ApplicationAugus't. 9, 1945,,SeriaINb. 609,858 In Switzerland September 26', 1944 It is known to cool the middle part of the cylinder liner of oppos'ed piston internal CO'II'IP' bust'ion engines by means of cooling passages bored obliquely to the" cylinder axis; This so-- lution has the disadvantage that the" strength of the wall which lies' Ibetween the coolin passages and the surface heated by'thegases is lowest in the middle sectional plane of thecylinder and increases to both sides. The most intensive cooling effect, however, is desirable in the zone in which the piston rings are situated when the pistons are in their inner dead centre;

This disadvantage is' removed by the present" invention by arranging the passages in such a way thattheir distance from the cylinder axis is at a minimum outside'the middle plane of the cylinder, and in particular in the zone in which the piston rings are situated when the pistons are in their inner dead centre- The end is thus attained that the part of the cylinder liner over which'the piston rings pa-ss' remains cool, a fact which has a favourable influence. on they working of the. engine and its consumption of lubricating oil' and which greatly reduces the heat stresses occurring in the liner.

A number of embodimentsof the invention are shown in the accompanying drawings, in which Fig. I is" a longitudinal section through the cylinder liner. of an opposed-piston engine; designed according to the invention;

Fig. 2 shows the middle part of the liner from Fig. 1 to a larger scale;

Fig. 3 shows another design of the middle part of the cylinder liner;

Fig. 4 is the cross-section along the line IV-- IV of Fig. 2; and

Fig. 5 shows in cross-sectional elevation a further form of cylinder liner.

In Fig. 1 the cylinder liner l is formed in one piece. The two pistons 2 and 3 are shown in the outer dead centre. The inner dead centre of the pistons 2 and 3 is indicated by chain-dotted lines. The scavenging and supercharging air enters through the scavenging port 4; the combustion gases issue through the exhaust port 5. For cooling the strengthened middle part 6, cooling medium is introduced into the cooling jacket 3| through the inlet branch 32. cooling medium flows through passages 8 arranged in the strengthened middle part obliquely to the cylinder axis entering these passages at 29 and leaving at 30. It then passes out of the cooling jacket 3| through the outlet branch 33.

In the arrangement according to the invention the strengthened middle part 6 is bored from The entrance. orifices 29 and exit orifices 30 on its inlet and outlet sidesrespectively in such a way that the" axes of the passages originating on each sideibelon'g. to" the generating lines of a single- 5 sided hyperboloid of rotation whose axis of rocation. ai'coincide'si with the cylinder axis. Each pair of such pasages 8, 9 intersects in the middle plane of the. cylinder, so that a continuous channel istformed' for the cooling medium. The

.- valvesv (for example fuel and starting valves) are designated by the numeral m.

Fig. 2 shows thestrengthened middle part a to; a larger scale. The sectional plane of the drawing cuts the ellipses l2, l3, l4, l5; 15; ll, l d

I 8 l9 out of the-single cooling passages. The

broken line a-a defines the surface containing section as straight lines which cut the middleplane, for instance, at 28. The points at which these passages open into the inlet end surface of the strengthened middle part 6 are designated 29, and the points at Which these passages come nearest to the cylinder axis are designated 34, which corresponds to the region of pointAin Fig. .2.

Fig. 3 again shows the strengthened middle part 6 of the cylinder liner I. The cooling passages are here arranged in a different manner. The middle part 6 is bored from the two sides 6', 6", and two groups of passages 20, 25, 2|, 25 are provided on each side, the axes of each group lying on a regular cone whose axis is the cylinder axis. Each pair of passages 20, 2| intersect in the middle plane of the cylinder. The passages 20, 2| are closed at 22, 23, so that the cooling medium flow follows the line C, D, E, F, G, the smallest distance of the passages from the cylinder axis presenting itself at D and F outside the middle plane E of the cylinder.

In order to come within the scope of the present invention, it is neither necessary that the passages be arranged symmetrically about the middle plane of the cylinder nor that the pairs of passages intersect on that middle plane. In the middle plane of the cylinder openings are provided for the fuel valves and possibly also for provided on the inner side which run parallel to the passages in the middle part of the liner and thus relieve the hot zone of the wall, the recesses 26 reaching approximately to the cooled zone. deeply still, as shown by recess 21.

I claim:

1. A cylinder liner for opposed piston internal combustion engines having a strengthened middle part surrounding the combustion chamber, a plurality of passages in the wall of said middle part oblique to the axis of the cylinder for the circulation of a cooling medium, the distance of said passages from the cylinder axis decreasing to minimum outside the middle transverse sectional plane of the cylinder.

2. A cylinder liner according to claim 1, in which the distance of the cooling passages from the cylinder axis is smallest in the zones in which the piston rings are situated when the pistons are at inner dead center.

3. A cylinder liner for opposed piston internal combustion engines having a strengthened middle part surrounding the combustion chamber, a plurality of passages in the wall of said middle part oblique to the cylinder axis for the circulation of a coolin medium, each ofsaid passages having two distinct parts meeting at a vertex substantially in the middle transverse sectional plane of the cylinder, the two parts of each passage being so arranged that their respective distances from the cylinder axis decrease to a minimum in the zones in which the piston rings are situated when the pistons are at inner dead center.

4. A cylinder liner according to claim 3, in which the two parts of each passage are symmetrically arranged with respect to the middle transverse sectional plane of the cylinder.

5. A cylinder liner for opposed piston internal combustion engine having a strengthened middle part surrounding the combustion chamber, a plurality of passages in the wall of said middle part oblique to the cylinder axis for the circula- The recess may also enter the wall more tion of a cooling medium, each of said passages having two straight parts meeting at a vertex substantially in the middle transverse sectional plane of the cylinder, each group of passage parts lying on the same side of said plane being so arranged that the axes of the passage parts of each group belong to the generating lines of a single sided hyperboloid of revolution whose axis coincides with that of the cylinder.

6. A cylinder liner for opposed piston internal combustion engines having a strengthened middle part surrounding the combustion chamber, two rows of passages in the wall of said middle part for the circulation of a cooling medium, each of said passages having two distinct parts intersecting each other, the axis of every such part lying in a regular cone whose axis coincides with that of the cylinder, the vertices of intersection of the parts of one row of passages lying in the zone in which the piston rings of one of the pistons are situated when that piston is at inner dead center, the vertices of intersection of the parts of the other row of passages lying in a zone in which the piston rings of the other of the pistons are situated'when that piston is at inner dead center, and corresponding parts of passages in one row intersecting corresponding parts of passages in the other row at vertices in substantially the middle transverse sectional plane of the cylinder.

7. A cylinder liner according to claim 1 in which recesses open to the combustion chamber are arranged in its middle part.

8. A cylinder liner according to claim 1 in which recesses open to the combustion are arranged in its middle part parallel to the cooling passages.

HANS STEINER.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Nmnber Name Date 1,410,319 Junkers Mar. 21, 1922 2,171,783 Dennison Sept. 5, 1939 2,193,884 Retschy Mar. 19, 1940 2,244,323 Antonsen et a1 June 3, 1941 

